1. Field of the Invention
This invention involves an adjustable hydraulic damper. and, more particularly, a peripherally valved, bi-directional, hydraulic damper which is adjustable through external deformation of the hydraulic cylinder wall.
2. Description of the Prior Art
Previously developed adjustable hydraulic dampers have been complex in construction, utilizing external valves or ports, springs, positive sealing pistons, and other wearing parts. Such adjustable hydraulic dampers have experienced problems in reliability, cost, maintenance, and difficulty in adjustment. These shortcomings are particularly evident in the application of adjustable hydraulic dampers to prosthetic joints, particularly knee joints, where a compact, simple, reliable bi-directional damper, where the damping action is externally and separately adjustable in each direction, is needed.